1. Field of the Invention
This invention is an envelope package for protecting fragile sheets, especially glass sheets, in transit and in storage.
2. Description of the Prior Art
Glass sheets, especially curved automotive glass sheets, are presently shipped and stored in sleeves made of two corrugated sheets which are sewn together along two or three sides. U.S. Pat. No. 3,860,116 discloses a packaging device for glass articles. The package comprises front and rear panels which are sewn together adjacent to a bottom edge and two side edges to define an envelope structure. Surprisingly, much the same package is used today for curvilinear automotive glass sheets.
There are some practical problems with the sewn envelope package. The sewing of corrugated board and the like is a very slow process which is rather inefficient. The process becomes even more inefficient when needles break and the process is stopped for the replacement of needles. A sewn envelope structure has performance problems as well. When a needle perforates the front and back panels, it effectively scores those panels and weakens them, predisposing the envelope structure to failure at the perforations. As automotive glass has become more curved, the strain the glass imposes on the panels where they are sewn together has increased, thereby increasing the frequency of this type of failure. Such a failure exposes the most vulnerable part of a glass panel, which is an edge.
U.S. Pat. No. 2,917,166 discloses a package especially adapted for automotive windshields. This package is essentially constructed around a glass panel and has front and rear panels which are held together by staples and tape or metal straps. Accordingly, the package requires a great deal of labor to secure it to and around a glass panel.
U.S. Pat. No. 3,028,001 discloses a packaging device especially suited for curved glass panels such as windshields. The package comprises front and rear panels and tabs adjacent upper and lower edges of the front panel. There are slots above the tabs adjacent the upper edge and below the lower edge of the of the front panel. A glass panel is positioned on the front panel; the tabs are folded over the edges of the glass panel; and the rear panel is brought into contact with the glass panel; slots in the rear panel are then aligned with the slots above and below the tabs of the front panel. Next, tape is wrapped around the front and rear panels, passing through the aligned slots therein. The tape secures the tabs in their folded positions where they engage the glass panel. This package is also literally constructed around a glass panel.
U.S. Pat. No. 3,166,188 discloses a packaging device for automotive glass. The package comprises a cover panel and a supporting panel. Upper and lower flaps formed in the cover panel are folded to engage a sheet of glass and then banding straps or strips of tape are passed around the package to secure the flaps in position where they engage and retain the glass sheet in place. The ends of the package are folded inwardly to engage the side edges of the glass sheet and the entire package is stapled to secure the end portions adjacent to the side edges and to secure the cover panel to the supporting panel. Again, this package is literally constructed around a glass sheet.
U.S. Pat. No. 2,740,518 discloses an envelope within a box concept for packaging glass sheets, especially curved automotive glass. The sheet is received in an envelope comprised of a bottom protective liner and a top protective liner. The bottom liner has foldable flaps on four edges which are bent inwardly, preliminarily, to engage the edges of a glass sheet.
The present invention, in one embodiment, is an article of sheet form and a shipping case for the article. The shipping case comprises a paperboard sheet which is folded upon itself along a fold line, and is so shaped that, in its folded condition, it has first and second polygonyl sheet members with opposed major surfaces and n edges. The central portions are substantially coextensive with the major surfaces of the article, while the n edges surround the central portions of the major surfaces. One of the edges is common to the first and second sheet members along the fold line. There are at least three pairs of opposed, substantially coextensive flaps, one of which extends outwardly beyond the central portions of the members to the fold line and each of the others of which extends outwardly beyond the central portions of the members to another edge. Each of the flaps is integral with the central portion of one of the members, which are positioned so that one is on each side of the article and the article is sandwiched between the central portions of the members. There is a body of an adhesive disposed between facing surfaces of the flaps of each of the pairs. Each of the bodies of adhesive is operable to prevent movement relative to one another of the flaps between whose facing surfaces it is disposed, and to prevent the article from sliding between the facing surfaces of the flaps between whose facing surfaces it is disposed.
In a preferred embodiment, the shipping case according to the invention additionally includes at least one flap which is structurally integral with one of the members along an edge thereof, and is folded around a peripheral edge of the article and adhered by a body of adhesive to the exterior surface of the central portion of the second of said members.
It is, therefore, an object of the invention to provide an article of sheet form and a shipping case for the article.
Other objects and advantages will be apparent from the disclosure herein of preferred embodiments, reference being made to the attached drawings.
FIG. 1 is a plan view of a paperboard sheet which has a suitable shape, and to which glue has been applied, so that a lower portion of the sheet can be folded over the upper portion thereof and the glue can be hardened to produce a shipping case into which an appropriately sized sheet of glass or other material can be inserted.
FIG. 2 is a plan view of the shipping case produced by folding the lower portion of the sheet of FIG. 1 over the upper portion thereof, and hardening the glue.
FIG. 3 is sectional view taken along the line 3xe2x80x943 of FIG. 2, and showing the structure of the portion of the shipping case of FIG. 2 which is adjacent a fold line along which the upper and lower portions of the sheet are connected.
FIG. 4 is a view in section taken along the line 4xe2x80x944 of FIG. 2, and showing the structure of the portion of the shipping case of FIG. 2 which is adjacent a side edge thereof.
FIG. 5 is a plan view of another paperboard sheet which has a suitable shape, and to which glue has been applied, so that a lower portion of the sheet can be folded over the upper portion thereof and the glue can be hardened to produce a shipping case into which an appropriately sized sheet of glass or other material can be inserted.
FIG. 6 is a plan view of the shipping case produced by folding the lower portion of the sheet of FIG. 5 over the upper portion thereof, and hardening the glue.
FIG. 7 is a sectional view taken along the line 7xe2x80x947 of FIG. 6, and showing the structure of one portion of the shipping case of FIG. 6 which is adjacent a fold line along which the upper and lower portions of the sheet are connected.
FIG. 8 is a view in section taken along the line 8xe2x80x948 of FIG. 6, and showing the structure of another part of the portion of the shipping case of FIG. 6 which is adjacent the fold line along which the upper and lower portions of the sheet are connected
FIG. 9 is a plan view of still another paperboard sheet which has a suitable shape, and to which glue has been applied, so that a lower portion of the sheet can be folded over the upper portion thereof and the glue can be hardened to produce a shipping case into which an appropriately sized sheet of glass or other material can be inserted.
FIG. 10 is a plan view of the shipping case produced by folding the lower portion of the sheet of FIG. 9 over the upper portion thereof, and hardening the glue.
FIG. 11 is sectional view taken along the line 11xe2x80x9411 of FIG. 10, and showing the structure of one portion of the shipping case of FIG. 10 which is adjacent a fold line along which the upper and lower portions of the sheet are connected.
FIG. 12 is a view in section taken along the line 12xe2x80x9412 of FIG. 10, and showing the structure of another part of the portion of the shipping case of FIG. 10 which is adjacent the fold line along which the upper and lower portions of the sheet are connected.
FIG. 13 is a vertical sectional view similar to FIG. 12, but showing a portion of a shipping case that is disclosed in the prior art.
FIG. 14 is a view in vertical section showing the prior art shipping case of FIG. 13 after a typical failure has occurred.